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P4-IO-Jacks — Interfaces (Overview)

Overview of the four IO jacks and their operating modes.

Overview

The P4 module provides four IO jacks (physical connectors): IO-Jack 0 – IO-Jack 3. Each jack supports four operating modes — the most recently used interface access determines the active mode:

Mode Purpose
PORT Digital I/O with 4 bit (Pin0–Pin3) and Configuration of the other interfaces,
always with taskit Port-8 protocol
I²C I²C master, read/write via tunneled byte streams
UART Serial interface, configurable (baud rate, parity, …)
SPI SPI interface (configuration TBD)
ADC. ADC interface (configuration TBD)

The four ADC channels ADC0 – ADC3 are located exclusively on IO-Jack 0. The remaining jacks (1–3) have no ADC.

Jack/Mode Matrix

IO-Jack PORT I²C UART SPI ADC
IO-Jack 0 ✓ ✓ ✓ ✓ ADC0–ADC3
IO-Jack 1 ✓ ✓ ✓ ✓ –
IO-Jack 2 ✓ ✓ ✓ ✓ –
IO-Jack 3 ✓ ✓ ✓ ✓ –

Each jack can only have one mode active at a time. The four ADC channels are available only on IO-Jack 0.

Analog (ADC/DAC)

The four ADC channels (on IO-Jack 0) are addressed via the Ext-3 commands:

Code Command Function
40 AnalogSetMode ADC/DAC configuration (mode + 4-bit pad no.)
41 AnalogValue Read/write analog value (+ 4-bit pad no.)

Addressing

  • Jack selection happens in the transport address (MQTT topic / NATS subject): …/<Jack>/<Interface>, e.g. …/0/uart.
  • Pin/pad selection within a jack via a PAD mask (4 bit) or a direct PAD address.

Cross References